Acyl hydrazines



ACYL HYDRAZINES Arsenio A. Pessolano, Colonia, and Robert L. Clark, Woodbridge, NJ., assignors to Merck & Co., Inc.,

1 Railway, a corporation of New Jersey {Nb Drawing. Filed Oct. 15, 1951, Ser. No. 690,220 9 Claims. 01460-4045 wherein R representsa hydrogen atom or an alkyl, aryl. amalkyl, alkaryl or heterocyclic radical. Each of these radicals may be substituted or unsubstituted and, in the case. ,Ofithos'e radicals containing alkyl moieties, may be either; straightvchain or branched chain radicals.

,The compounds of this invention can be used as anticonyulsants without causing sedation and are also useful aspotentiators of barbiturate anesthesia.

iL r ve1 compounds are prepared by reacting {3,19- diph'enylhydracrylic acid hydrazide with an acylating agent. .The reaction is conducted in an organic base, with or without heat, or in a neutral solvent such as benzeneat-room temperature.

ii-The starting material for the preparation of the com- 'of this invention, N-(3,3-diphenyl-3 hydroxypropionyll'hydrazine, may be prepared by the reaction oflestrs of 3,3-diphenyl- 3-hydroxypropionic acid with hydrazine. The propionic acid esters may be prepared in turn by a Reformatsky reaction utilizing benzophenone, an ester ofan a-halo acetic acid such as ethyl bromoacetate,'and zinc. These reactions may be indicated by the following sequence of equations:

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2,944,07l' Patented July 5, 1960 ice and the acylafing agent in the presence of a suitable solvent. In order to control the course of the reaction it is frequently desirable to cool the reaction mixture during the addition of the reactants.

The reaction may be conducted in an organic base which is a solvent for the starting material. Suitable organic bases are in general tertiary amines, for example, triethylamine, pyridine, quinoline and the like. The organic base functions to remove any hydrogen chloride which is formed in the reaction, and the use of a base as a solvent permits higher temperatures to be utilized in the reaction. The reaction may be conducted at room temperature or at elevated temperatures if desired. The use of elevated temperatures is readily accomplished by means of a steam bath to heat the reaction mixture.

. The reaction may also be conducted in a neutral solvent. For this purpose, the reaction may be advanta-.

geously run at room temperatures in a substantiallyneutral, non-polar solvent such as hydrocarbon solvents of EXAMPLE 1 .N-(3,-3-ztiphenyl-3rhydroxypropionyl) N'-acetyl hydrazine- To 700ml. of dry benzene was added 182- g. of hemephenone and g. of freshly cleaned zinc granules, 20-30 mesh. The mixture was stirred rapidlyand heated to,

reflux. A solution of 185 g. of ethyl bromoacetate in 300 m1. of dry benzene was then added to the mixture over a period of2 hours, keeping the reaction mixture at gentle reflux during the addition. The resulting mixture was refluxed for another 3 hours and then cooled in ice and treated with a solution of 200 ml. of concentrated sulfuric acid and 1,000 ml. of water by adding the solution dropwise over a period of 1 hour. Ether was added and the organic layer was separated, washed with water and sodium bicarbonate solution, dried over magnesium sulphate and evaporated. Petroleum ether was then added to the residue and 179 g. of ethyl 3,3 diphenyl-3- hyd'roxypropionate in the form of needles having a melting point of 7780 C. was obtained.

This material was converted to the hydrazide without further purification as follows:

A mixture of 60 g. of the crude ethyl 3,3-diphenyl-3- hydroxypropionate and ml. of 85% hydrazine hydrate was heated on a steam bath for 1 hour. The reaction mixture was cooled and the hydrazide crystallized as white rods. The product N-(3,3-diphenyl-3ehydroxyv propionyl) hydrazine was obtained in a yield of 54.3 g. and was found to have a melting point of 130-13l C. This product and the product of additional runs was .used in the preparation of N-(3,3-diphenyl-3-hydroxypro pionyl) N'-acety1 hydrazine as follows:

To 425ml. of acetic anhydride maintained below 30 C. was added in portions g. of N-(3,3-diphenyl 3- hydroxypropionyl) hydrazine. As'the product began to crystallize toward the end of the addition, 1,000 ml. of ether was added to facilitate stirring. The resulting thick. suspension was stirred for 1 /2 hours andthenthevsolid I 3 N=(3,3=diph enyl-3-hydroxypropionyl) N'afiCfltYl hydrazine was removed by filtration. The product was obtained in a yield of 125 g. Recrystallization from absolute ethanol yielded a product having a melting point of 16.1.? 162 C.

For the sake of convenience, in the following examples N-(3,3-diphenyl-3-hydroxypropionyl) hydrazine will be referred to as the starting material.

EXAMPLE 2 N (3,3-diphenyl-3-hydr0xypropionyl) N'-isocqpr0yl; hydrazine In 15 ml. of pyridine was dissolved 2.56 g. of the starting material, and 1.40 g. of isocaproyl chloride was added to the solution. The solution was heated on a steam bath for 15 minutes. Water was added and an oil wasformed. The aqueous layer was decanted and the oil taken up in ether-benzene, washed with water, dried and evaporated. The solid weighed 3.0 g. It was dissolved in 9 ml. of methanol and 1 ml. of water was carefully added to the warm solution. 'Ihe product cryse t'allized as needles having a melting point of 131-132 C,

EXAMPLE 3 N- (3,3-diphenyl-3 hydroxypropionyl) drazine' In 15ml. of pyridine was dissolved 2.56 g. of starting material. To this solution was added 2.25 g. of lauroyl chloride. The reaction mixture was heated on a steam bath for 15 minutes and 100 ml. of water was added to precipitate the product. An oil formed whichv slowly solidified. The solid was collected and weighed l g. Upon recrystallization from absolute ethanol there were obtained small white crystals having a melting. point of 104-105 C.

N lauroyl hy- EXAMPLE 4 N-(3,3-diphenyl-3-hydroxypropionyl) N'-myristoyl hydrazine To a solution of 2.56 g. of starting material in 15 ml. of pyridine was added 2.50 g. of myristoylchloride. The reaction mixture was heated on astearn bath for 15 minutes, cooled and then 100 m1. of water was added. An oil formed which solidified on rubbing. The solid Was. col.- lectedand Weighed 4.5 g. Th solid product was dissolved in 35 ml. of absolute ethanol, filtered through Supercel and 3 ml. of water added to the warm solution. Small.

round white crystals having a melting point of 107-109 C. were collected.

EXAMPLE 5 N-(3,3-diphenyl-3-hydroxypropionyl) N'-pg alm itoyl hydrazine V EXAMPLE 6 N-(3,3-diphenyl-3-hydroxypropionyl) N'-phenylacetyl hydrazine To 50ml. of dry benzene was added 5.0 g. of starting material and 3.09 g. of phenylacetyl chloride. The hydrazine gradually went into solution and the reaction mixture became warm with the evolutionof hydrogen chloride. 'Severa'l minutes after there was complete solution, a svhitesolid began to crystallize. Petroleum ether was added and the solid was found to weight 6.8 g. The solid was taken up in ml. of warm absolute ethanol and crystallized as small hard needles. Recrystallization from dilute ethanol gave plates having a melting point of l33l34 C.

EXAMPLE 7 N-(3,3-diphenyI-S-hydrOxypropionyI) N-diphenylacetyl hydrazine r from absolute ethanol to give a crop of smallwhite nrysta ith a me p n of 174-l75-C.. I

E AM LES v N -(3,3-diphenyl-3 hydroxypropionyl) N' b'e nzqyl hydrazine To 0 o b n was added 5-,Q'gaof material and 2.82 g. of benzoyl chloride, Y The mixture became warm and a new solid formed. After 10 minutes the reaction mixture was solid. Petroleum ether was added and the mixture was allowed to stand for 15 minutes. The solid was found to weigh 6.3 g. Recrystallization from absolute ethanol gave a crop of'whitecrys tals having a melting point of 158-159" C. a

Other N-(3,3-diphenyl-3-hydroxypropionyl) l*l-'-acylh{ drazines which may be prepared in a manner similar tattle above examples include the N-propionyl, N-butyry1', H pentanoyl and similar alkanoy1'hydrazines. In addition, compounds such as N-(3,3ediphenyl-3-hydroxypropionyl) N'-naphthoyl hydrazine and theN'ecinnam'oyl, N thenoyl," N' nicotinoyl, N'-toluyl and other acyl hydrazinesof'the aroyl, aralkanoyl and alkaroyl series, as well as hydrazines substituted with a heterocyclic acyl radical maybe simi.-' larly prepared. F

The novel compounds of the instant invention are efleca: tive anti-convulsants and barbiturate potentiators when taken orally and may therefore be. administeredin form of capsules or tablets. The capsules should eontain; about 0.25 g. to about 0.50 g. of the pure. Nr.(i3;3.- d-l p y y yp p y ey1 hydrazine-s tablets should contain approximately 0.25 g. t about; 0. of the P y ydr in s a well: as asmall; amount of a lubricant such as magnesium stcarateaud, disintegrating agent such as cornstarch, The of this invention may also be utilized in other conventional formulations. j

Various changes and modifications of the invention-can be made, and to the extent that such variations incomes. rate the spirit of the instant invention, they are intended to be included within the scape of the appended claims.

What is claimed is:

1. A product selected from the group consisting of N-(3,3-diphenyl-3-hydroxypropionyl) N'.-acyl hydrazines of the general fromula iph ny h d oxypmhionyl)iltl' etyl' -l x3- P Y1-3-hydroxyp opiepyl)il'dau oyl hr: l

6 5. N-(3,3-diphenyl-3-hydroxypropiony1) N'-myristoyl OTHER REFERENCES hydrazine.

N (3,3 dipheny1 3 hydroxypropionyl) N, pa1mit0y1 Curtius. J. Prakt. Chem. [2], vol. 95 (1917), p. 199.

Chem. Abstracts, vol. 5, p. 3572 (1911), citing J. Prakt.

hydrazine Chem [21 v01 83 pp 513-5 0 (1905 ,,Z; ;1} 3 hydroxyprcplonyl) N phenyl 5 Chem. Abstracts, v01. 28, p. 5441 1934 citing Acta 8. N-(3,3-dipheny1-3-hydroxypropiony1) N' Acad. Aboensrs Math et Phys., vol. 6 #12 Aspelund, acetyl hydrazine. 15 Pages 9. N-(3,3-dipheny1-3-hydroxypropiony1) N-benzoyl Chem. Abstracts, vol. 48, p. 5189 (1954), citing Rend. d i 10 seminar fac sci univ. Cagliari, vol. 22, pp. 78-80 (1952),

Paggi et 211. References Cited in the fil f this patent J. Prakt. Chem. [2], vol. 95, p. 205 (1917) (Curtius),

Beilstein, 4th ed., vol. IX, 1st suppL, p. 153 (1932). UNITED STATES PATENTS 2,765,304 Siegrist et a1. Oct. 2, 1956 15 

1. A PRODUCT SELECTED FROM THE GROUP CONSISTING OF N-(3,3-DIPHENYL-3-HYDROXYPROPIONYL) N''-ACYL HYDRAZINES OF THE GENERAL FORMULA
 4. N-(3,3-DIPHENYL-3-HYDROXYPROPIONYL) N''-LAUROYL HYDRAZINE. 